Speaking to over 3,000 fire fighters at their annual convention in Philadelphia, the vice president said that Romney "means well" but that he and his party fail to grasp the motives of public sector workers who put their lives in jeopardy for others in their communities.

"I think part of the problem is I don't think he gets you," Biden said. "I don't think he really understands - I mean this sincerely - I don't think he understands what you're all about, what makes you tick, what makes you decide to go into this profession, which you couldn't pay enough to 90 percent of the population - including me - to do what you do every day."

Biden, who emotionally referenced the role of firefighters in saving his sons' lives in the 1972 crash that killed his wife and daughter, lamented a "perfect storm" of economic woes and anti-union campaigns that have hit at the core of the hook-and-ladder profession.

"They act like you're the community's problem," he said of Republican lawmakers aiming budget cuts and other reforms at unionized public sector workers. "As if you're not part of the community. As if somehow you're from some other place. As if you haven't been as affected by this recession as your neighbors have, not because you're a firefighter, because you're a middle class citizen."

The vice president, whose recent comments describing a de-facto "depression" for America's unemployed were vigorously highlighted by Republicans, on Wednesday described the country as "barely" out of the economic recession.

"This is about shared responsibility," he said, noting the administration's push for tax hikes on high earners. "You know as well as we do the country is out of this recession but barely and struggling to move forward. I mean, you have ... blood brothers, blood sisters, who because of this recession are out of work."

The Romney campaign responded with a statement from Fred Donnelly, a retired battalion chief of the Philadelphia fire department.

“Joe Biden can come to Philadelphia, and he can try and tell the hard working men and women of this city that he understands what we’ve been going through. But no matter what he says, he can’t cover up the words of the president," Donnelly said. "The President may think the private sector is ‘doing fine.’ He may want small businesspeople to believe that they ‘didn’t build that.’ But we know that he is simply out of touch with the struggles that middle-class Americans are going through, and that he doesn’t understand what drives the American economy.”

Biden's remarks, while perhaps slightly less pointed than a typical campaign speech, marked a public return to the partisan punches that preceded last week's massive shooting at an Aurora, Colorado theater.

Mentioning the heroism of rescue squads in that community, Biden lauded fire fighters for aiding at the massacre's scene and for dismantling the shooter's booby-trapped apartment.

"You were there ready to do whatever was needed if the worst happened," he said.